For example, Patent Document 1 discloses a method of detecting a fault of a control system by using an operation model.
However, operation models of diagnostic objects, such as operation models of apparatus each to be produced only by one or a small number and an apparatus being developed, may not be obtained.
Accordingly, the method disclosed in Patent Document 1 cannot be applied to such the apparatus.
[Patent Document 1] JP Publication of Unexamined Patent Application S57-041708